# Implementation notes

The student request is preserved in prompt.txt. This implementation extends only the index.html, style.css and app.js supplied in ../07-lfo/. The first complete version is preserved in attempts/001/.

## Choices

- The page uses local HTML, CSS and JavaScript with native Web Audio. It requires no libraries, services or sound files.
- Manual, LFO and Smooth random are exclusive modes. Automatic modes own either volume or filter frequency. The corresponding manual slider is disabled until Manual is selected. The other parameter remains available.
- Smooth random has separate minimum and maximum settings for volume and frequency. Target interval and transition duration are independent. Limits are 0–100% for volume and 20–16,000 Hz for frequency. Interval is 0.1–30 seconds and transition is 0.05–30 seconds. Invalid input falls back to the last valid value. Crossing one bound moves the other bound to match.
- Each new target starts from the current segment value. Audio automation and the history trace use the same piecewise cosine interpolation. Frequency values move logarithmically. No LFO depth reaches an AudioParam while random mode owns it.
- A live trace shows the last 20 seconds, current value, target and time until the next target. Its scale follows the bounds. Equal bounds produce a constant value.
- Try slow wind selects generated pink noise, a low-pass filter at about 1,600 Hz, volume between 8% and 28%, a new target every 5 seconds and an 8-second transition. It configures the sound without starting audio. If already playing, it updates that sound.
- The previous noise colours, filter options, response graph, source level, envelope, Release and Stop all remain available. The low source gain, filter resonance trim and compressor are inherited. AudioContext creation remains inside the Start button handler.

## Checks

- node --check app.js passed.
- A static HTML check found no duplicate IDs or unresolved querySelector ID references. All linked assets are local.
- Inspected the mode changes, interrupted random segments, bounds, destination changes and stop cleanup in the source.

## Limits

Browser interaction, audio capture and listening checks are assigned to the parent agent. No browser, server or live audio test was run in this worker. New random targets use browser timers; in a throttled background tab, a transition may finish and hold before the next target arrives. Scheduled fades still run through the audio engine.